OSF Use last four pairs of hex digits of Ethernet Interface, hardware address in /var/adm/messages

MP-RAS run ildconfig

Use the 12-digit number displayed in NODE field for first csma/cd adapter.

Microsoft Windows (several alternatives)

Install Rational ClearCase and run the command clearlicense -hostid or just hostid

Run ipconfig -all and look for the Physical Address which will display similarly to this: 00-60-97-2D-2E-D9

If you have Microsoft® Developer Studio® installed, in the bin directory (for example c:\msdev\bin) there is a file called uuidgen.exe. Run the executable, which will return output similar to: 8963f520-e965-11d0-91f9-00a024c23b99 The last string of numbers is the Host ID, so in this example the Host ID is 00a024c23b99.

On the Rational ClearCase CD or in the ClearCase Release Area, look for an executable called hostid.exe. Copy this file to the license host and run it. The results will be displayed in a GUI.